The learning curve in transcatheter aortic valve implantation clinical studies: A systematic review

Impact of proficiency in the transcatheter aortic valve implantation procedure on clinical outcomes: a single center retrospective study

BACKGROUND

We used transcatheter aortic valve implantation (TAVI) procedure time to investigate the association between surgical team maturity and outcome.

METHODS

Among patients who underwent TAVI between October 2015 and November 2019, those who had Sapien™ implanted with the transfemoral artery approach were included in the analysis. We used TAVI procedure time and surgery number to draw a learning curve. Then, we divided the patients into two groups before and after the number of cases where the sigmoid curve reaches a plateau. We compared the two groups regarding the surveyed factors and investigated the correlation between the TAVI procedure time and survey factors.

RESULTS

Ninety-nine of 149 patients were analysed. The sigmoid curve had an inflection point in 23.2 cases and reached a plateau in 43.0 cases. Patients in the Late group had a shorter operating time, less contrast media, less radiation exposure, and less myocardial escape enzymes than the Early group. Surgical procedure time showed the strongest correlation with the surgical case number.

CONCLUSION

The number of cases required for surgeon proficiency for isolated Sapien™ valve implantation was 43. This number may serve as a guideline for switching the anesthesia management of TAVI from general to local anesthesia.

Results and insights after 413 TAVI procedures performed by cardiac surgeons on their own

OBJECTIVES

Current evidence on transcatheter aortic valve implantation (TAVI) has been generated exclusively by cardiology studies and no operative data from cardiac surgeons are available. Here, we describe the development of our TAVI programme and report the results of transfemoral (TF) TAVI done by cardiac surgeons on their own.

METHODS

This study included all the TAVI procedures on native valve performed at Cardiac Surgery Unit, Ospedali Riuniti di Ancona, during the period October 2018 to July 2022. Relevant prospectively collected preoperative, intraprocedural and postoperative data were retrieved from the Institutional database.

RESULTS

A total of 413 patients were included in the study. Mean patients' age was 82 years and among them 44% (180/413) were male. STS score was 3.1% (2.2-4.4). Eighty patients underwent transapical TAVI and 333 patients had a TF approach. We progressively moved from transapical TAVI towards TF procedures that are now routinely performed on conscious sedation and using a fully percutaneous approach. After TF TAVI, 30-day mortality rate was 1%, cerebral stroke occurred in 2% of the cases, permanent pacemaker implantation was necessary in 23% of the patients and in 6% of the cases there was a moderate/severe degree of aortic regurgitation. There was no association between operators performing TAVI and 30-day mortality.

CONCLUSIONS

The acquisition of catheter-based skills and an adequate training allowed cardiac surgeons to perform on their own awake and fully percutaneous TF TAVI with similar results when compared with major randomized clinical trials and registries' experiences.

The effect of the learning curve on paravalvular aortic regurgitation and mid-term mortality in transfemoral transcatheter aortic valve implantation

OBJECTIVE

Paravalvular aortic regurgitation is an important independent mortality predictor in transcatheter aortic valve implantation (TAVI). Our study evaluated the association between paravalvular aortic regurgitation and mid-term mortality in relation with the learning curve, in patients with severe aortic stenosis who underwent transfemoral TAVI in the first 3 years since the establishment of the program.

METHODS

Patients with severe aortic stenosis who underwent transfemoral TAVI between 2017 and 2020 were included in the analysis. Paravalvular aortic regurgitation was assessed by transthoracic echocardiography at 48 hours after the procedure. All-cause mortality was evaluated after 30 days and at mid-term follow-up.

RESULTS

Paravalvular aortic regurgitation ≥grade II was associated with mid-term all-cause mortality (OR 4.4; 95%CI 1.82-11.55; p < 0.001), their prevalence declining after the first 60 cases. Baseline characteristics did not significantly differ in the first 60 patients from the rest of the cohort. Male sex (p = 0.006), advanced age (p = 0.04), coronary artery disease (p = 0.003), or elevated STS Score (p = 0.02) influenced mid-term survival. When adjusting for the presence of these factors, only age (OR 1.1; 95%CI 1.0-1.2), paravalvular aortic regurgitation ≥grade II (OR 3.9; 95%CI 1.3-12.9), and the number of days spent in the intensive care unit (OR 1.4; 95%CI 1.1-1.8) were independent predictors of mid-term all-cause mortality.

CONCLUSIONS

In a group of patients with severe aortic stenosis who underwent transfemoral TAVI in the first 3 years since the establishment of the program, paravalvular aortic regurgitation ≥grade II was associated with mid-term mortality, both declining after the first 60 cases.

The cost-effectiveness of transcatheter aortic valve implantation: exploring the Italian National Health System perspective and different patient risk groups

OBJECTIVES

To assess the cost-effectiveness (CE) of transcatheter aortic valve implantation (TAVI) in Italy, considering patient groups with different surgical risk.

METHODS

A Markov model with a 1-month cycle length, comprising eight different health states, defined by the New York Heart Association functional classes (NYHA I-IV), with and without stroke plus death, was used to estimate the CE of TAVI for intermediate-, high-risk and inoperable patients considering surgical aortic valve replacement or medical treatment as comparators according to the patient group. The Italian National Health System perspective and 15-year time horizon were considered. In the base-case analysis, effectiveness data were retrieved from published efficacy data and total direct costs (euros) were estimated from national tariffs. A scenario analysis considering a micro-costing approach to estimate procedural costs was also considered. The incremental cost-effectiveness ratio (ICER) was expressed both in terms of costs per life years gained (LYG) and costs per quality adjusted life years (QALY). All outcomes and costs were discounted at 3% per annum. Univariate and probabilistic sensitivity analyses (PSA) were performed to assess robustness of results.

RESULTS

Over a 15-year time horizon, the higher acquisition costs for TAVI were partially offset in all risk groups because of its effectiveness and safety profile. ICERs were €8338/QALY, €11,209/QALY and €10,133/QALY, respectively, for intermediate-, high-risk and inoperable patients. ICER values were slightly higher in the scenario analysis. PSA suggested consistency of results.

CONCLUSIONS

TAVI would be considered cost-effective at frequently cited willingness-to-pay thresholds; further studies could clarify the CE of TAVI in real-life scenarios.

Team-Based Learning and Lecture-Based Learning: Comparison of Sudanese Medical Students' Performance

AIM

Students' performance in TBL compared to LBL needs to be evaluated. This study aimed to compare students' performance in team-based learning and traditional lectures.

METHODS

A total of 176 class 4 and 202 class 6 medical students from University of Bahri, Khartoum, Sudan, participated in the study during 2018. Experienced staff were selected to conduct the teaching and assessment of the two groups, using the standard team-based learning procedure (iRAT, gRAT and AppT) in the first topic and the lecture-based learning procedure in the second, within the same time limit for the two methods.

RESULTS

The two classes overall mean score has a significant 5.1 points difference (p<0.001; 95% CI: 3.5, 6.0). Separate analysis showed consistency of superiority of TBL to LBL in either gender. A remarkable difference was observed when we compared the two methods in class 6 separately from class 4. Class 6 mean score was high for both TBL and LBL (77.2 and 70.2, respectively), with a significant mean difference of 7.0 (p<0.001; 95% CI: 5.1, 8.9). In class 4, the score was lower for both methods (mean of 62.8 for TBL and 59.9 for LBL). The mean difference of 2.95 points was still significant (p<0.05; 95% CI: 0.46, 5.43). Separate multivariate linear regression for TBL and LBL showed no significant difference in performance of males and females in either method. Controlling for gender in TBL, class 4 had a mean of -14.26 points, (p<0.001; 95% CI: -12.54, -15.98) less than class 6. Similarly, in LBL, class 4 had a mean of -10.18 points (p<0.001, 95% CI: -7.02, -13.35), less than class 6.

CONCLUSION

Students' performance using team-based learning was superior to lecture-based learning, irrespective of students' gender, noticeable among senior students.